I tried to set up soundmodem as an AX.25 device in order to run xastir on my machine. Unfortunately, Ubuntu by default has a bunch of services installed that prevent this. (Not so much prevent it as try to shove 100k of data through the 1200-baud soundmodem, which kills it and drives you nutty if the audio is turned up.)

Here’s what I did to get around this:

1. Change /etc/samba/smb.conf to include only the eth0 interface.

interface = eth0

2. Go into /etc/cups/cupsd.conf and turn off broadcasting (instructions here):

# Browsing was on.
#Browsing On
Browsing Off
BrowseInterval 0
# end trying to get around sm0 problem